/**
    * This file Copyright (c) 2013-2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.mediaeditor;
  
  import info.magnolia.event.EventBus;
  import info.magnolia.event.HandlerRegistration;
  import info.magnolia.i18nsystem.SimpleTranslator;
  import info.magnolia.ui.actionbar.ActionbarPresenter;
  import info.magnolia.ui.actionbar.ActionbarView;
  import info.magnolia.ui.api.action.ActionDefinition;
  import info.magnolia.ui.api.action.ActionExecutionException;
  import info.magnolia.ui.api.action.ActionExecutor;
  import info.magnolia.ui.api.app.AppContext;
  import info.magnolia.ui.api.availability.AvailabilityDefinition;
  import info.magnolia.ui.api.message.Message;
  import info.magnolia.ui.api.message.MessageType;
  import info.magnolia.ui.api.view.View;
  import info.magnolia.ui.mediaeditor.action.availability.MediaEditorAvailabilityChecker;
  import info.magnolia.ui.mediaeditor.data.EditHistoryTrackingProperty;
  import info.magnolia.ui.mediaeditor.data.EditHistoryTrackingPropertyImpl;
  import info.magnolia.ui.mediaeditor.definition.MediaEditorDefinition;
  import info.magnolia.ui.mediaeditor.event.MediaEditorCompletedEvent;
  import info.magnolia.ui.mediaeditor.event.MediaEditorCompletedEvent.CompletionType;
  import info.magnolia.ui.mediaeditor.event.MediaEditorCompletedEvent.Handler;
  import info.magnolia.ui.mediaeditor.event.MediaEditorInternalEvent;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.commons.io.IOUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Implementation of {@link MediaEditorPresenter}.
   */
  public class MediaEditorPresenterImpl implements MediaEditorPresenter, ActionbarPresenter.Listener, MediaEditorInternalEvent.Handler, EditHistoryTrackingProperty.Listener {
      private static final Logger log = LoggerFactory.getLogger(MediaEditorPresenterImpl.class);
  
      private MediaEditorView view;
      private ActionbarPresenter actionbarPresenter;
      private MediaEditorDefinition definition;
      private AppContext appContext;
      private EditHistoryTrackingProperty dataSource;
      private EventBus eventBus;
      private ActionExecutor actionExecutor;
      private HandlerRegistration internalMediaEditorEventHandlerRegistration;
      private Set<HandlerRegistration> completionHandlers = new HashSet<>();
      private final SimpleTranslator i18n;
      private final MediaEditorAvailabilityChecker mediaEditorAvailabilityChecker;
  
      public MediaEditorPresenterImpl(
              MediaEditorDefinition definition,
              EventBus eventBus,
              MediaEditorView view,
              ActionbarPresenter actionbarPresenter,
              AppContext appContext,
              SimpleTranslator i18n,
              MediaEditorAvailabilityChecker mediaEditorAvailabilityChecker) {
          this.eventBus = eventBus;
          this.view = view;
          this.actionbarPresenter = actionbarPresenter;
          this.definition = definition;
          this.appContext = appContext;
         this.i18n = i18n;
         this.mediaEditorAvailabilityChecker = mediaEditorAvailabilityChecker;
         this.actionbarPresenter.setListener(this);
         this.internalMediaEditorEventHandlerRegistration = eventBus.addHandler(MediaEditorInternalEvent.class, this);
         this.view.asVaadinComponent().addDetachListener(event -> dataSource.purgeHistory());
     }
 
     @Override
     public void setActionExecutor(ActionExecutor actionExecutor) {
         this.actionExecutor = actionExecutor;
     }
 
     @Override
     public View start(final InputStream stream) {
         try {
             final ActionbarView actionbar = actionbarPresenter.start(definition.getActionBar(), definition.getActions());
             updateActionbar();
             this.dataSource = new EditHistoryTrackingPropertyImpl(IOUtils.toByteArray(stream), i18n);
             this.dataSource.setListener(this);
             view.setActionBar(actionbar);
             switchToDefaultMode();
             return view;
         } catch (IOException e) {
             errorOccurred(i18n.translate("ui-mediaeditor.mediaeditorPresenter.errorWhileEditing") + " ", e);
             log.error("Error occurred while editing media: " + e.getMessage(), e);
         } finally {
             IOUtils.closeQuietly(stream);
         }
         return null;
     }
 
     @Override
     public View getView() {
         return view;
     }
 
     @Override
     public void onSubmit(MediaEditorInternalEvent event) {
         dataSource.commit();
         complete(CompletionType.SUBMIT);
     }
 
     @Override
     public void onCancelAll(MediaEditorInternalEvent event) {
         dataSource.revert();
         complete(CompletionType.CANCEL);
     }
 
     @Override
     public void onLastActionCancelled(MediaEditorInternalEvent e) {
         switchToDefaultMode();
     }
 
     @Override
     public void onLastActionApplied(MediaEditorInternalEvent e) {
         switchToDefaultMode();
     }
 
     private void switchToDefaultMode() {
         doExecuteMediaEditorAction(definition.getDefaultAction());
     }
 
     @Override
     public HandlerRegistration addCompletionHandler(Handler handler) {
         HandlerRegistration hr = eventBus.addHandler(MediaEditorCompletedEvent.class, handler);
         completionHandlers.add(hr);
         return hr;
     }
 
     @Override
     public void onActionbarItemClicked(String actionName) {
         doExecuteMediaEditorAction(actionName);
     }
 
     @Override
     public MediaEditorDefinition getDefinition() {
         return definition;
     }
 
     private void complete(CompletionType completionType) {
         InputStream is = new ByteArrayInputStream(dataSource.getValue());
         eventBus.fireEvent(new MediaEditorCompletedEvent(completionType, is));
         clearEventHandlers();
     }
 
     private void clearEventHandlers() {
         internalMediaEditorEventHandlerRegistration.removeHandler();
         for (HandlerRegistration hr : completionHandlers) {
             hr.removeHandler();
         }
     }
 
     private void doExecuteMediaEditorAction(String actionName) {
         try {
             actionExecutor.execute(actionName, this, view, dataSource);
         } catch (ActionExecutionException e) {
             errorOccurred(i18n.translate("ui-mediaeditor.mediaeditorPresenter.actionExecutionException") + " ", e);
             log.warn("Unable to execute action [" + actionName + "]", e);
         }
     }
 
     @Override
     public void errorOccurred(String message, Throwable e) {
         Message error = new Message(MessageType.ERROR, message, e.getMessage());
         appContext.sendLocalMessage(error);
     }
 
     protected void updateActionbar() {
         Map<String, ActionDefinition> actionsDefinition = definition.getActions();
         for (Map.Entry<String, ActionDefinition> action : actionsDefinition.entrySet()) {
             AvailabilityDefinition availabilityDefinition = action.getValue().getAvailability();
             if (mediaEditorAvailabilityChecker.isAvailable(availabilityDefinition)) {
                 actionbarPresenter.enable(action.getKey());
             } else {
                 actionbarPresenter.disable(action.getKey());
             }
         }
     }
 }